Circuit formation method and circuit formation device

ABSTRACT

A circuit formation method includes a wiring formation step of forming a wiring by applying a metal-containing liquid containing nanometer-sized metal fine particles onto a base and firing the metal-containing liquid, a paste application step of applying a resin paste containing micrometer-sized metal particles to be connected to the wiring formed in the wiring formation step, and a component placement step of placing a component having an electrode on the base, such that the electrode is in contact with the resin paste applied in the paste application step.

TECHNICAL FIELD

The present application relates to a circuit formation method of acircuit including a wiring that is formed by using a metal-containingliquid containing nanometer-sized metal fine particles, and a circuitformation device thereof.

BACKGROUND ART As described in the following Patent Literature, atechnique for forming a wiring, using a metal-containing liquidcontaining nanometer-sized metal fine particles, has been developed.PATENT LITERATURE

Patent Literature 1: JP-A-11-163499

BRIEF SUMMARY Technical Problem

Appropriate formation of a circuit including a wiring, being formedusing a metal-containing liquid, is ensured.

Solution to Problem

In order to solve the above problems, the present specificationdiscloses a circuit formation method including a wiring formation stepof forming a wiring by applying a metal-containing liquid containingnanometer-sized metal fine particles onto a base and firing themetal-containing liquid, a paste application step of applying a resinpaste containing micrometer-sized metal particles to be connected to thewiring formed in the wiring formation step, and a component placementstep of placing a component having an electrode on the base, such thatthe electrode is in contact with the resin paste applied in the pasteapplication step.

In order to solve the above problems, the present specificationdiscloses a circuit formation device including a first applicationdevice configured to apply a metal-containing liquid containingnanometer-sized metal fine particles, a second application deviceconfigured to apply a resin paste containing micrometer-sized metalparticles, a firing device configured to fire the metal-containingliquid, a holding device configured to hold a component having anelectrode, and a control device, in which the control device includes awiring formation section configured to form a wiring by applying themetal-containing liquid onto a base by the first application device andfiring the metal-containing liquid by the firing device, a pasteapplication section configured to apply the resin paste by the secondapplication device to be connected to the wiring formed by the wiringformation section, and a component placement section configured to placethe component on the base by the holding device, such that the electrodeis in contact with the resin paste applied by the paste applicationsection.

Advantageous Effects

According to the present disclosure, the appropriate formation of thecircuit including the wiring formed using the metal-containing liquid isensured by connecting the electrode of the component and the wiring viathe resin paste.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing a circuit formation device.

FIG. 2 is a block diagram showing a control device.

FIG. 3 is a cross-sectional view showing a circuit in a state where aresin laminate is formed.

FIG. 4 is a cross-sectional view showing the circuit in a state where awiring is formed on the resin laminate.

FIG. 5 is a cross-sectional view showing the circuit in a state where anelectronic component is mounted.

FIG. 6 is a cross-sectional view showing the circuit in a state wherethe electronic component is peeled off.

FIG. 7 is a cross-sectional view showing the circuit in a state wherethe wiring is formed by a method of a first embodiment.

FIG. 8 is a cross-sectional view showing the circuit in a state whereconductive resin paste is formed by the method of the first embodiment.

FIG. 9 is a cross-sectional view showing the circuit in a state wherethe electronic component is mounted by the method of the firstembodiment.

FIG. 10 is a cross-sectional view showing the circuit in a state wherethe conductive resin paste is formed by a method of a second embodiment.

FIG. 11 is a cross-sectional view showing the circuit in a state wherethe electronic component is mounted by the method of the secondembodiment.

FIG. 12 is a cross-sectional view taken along a line AA in FIG. 11.

DESCRIPTION OF EMBODIMENTS First Embodiment

FIG. 1 shows circuit formation device 10. Circuit formation device 10includes conveyance device 20, first shaping unit 22, second shapingunit 24, third shaping unit 26, mounting unit 27, and control device(see FIG. 2) 28. Conveyance device 20, first shaping unit 22, secondshaping unit 24, third shaping unit 26, and mounting unit 27 aredisposed on base 29 of circuit formation device 10. Base 29 has agenerally rectangular shape, and in the following description, alongitudinal direction of base 29 is referred to as an X-axis direction,a short direction of base 29 is referred to as a Y-axis direction, and adirection orthogonal to both the X-axis direction and the Y-axisdirection is referred to as a Z-axis direction.

Conveyance device 20 includes X-axis slide mechanism 30 and Y-axis slidemechanism 32. X-axis slide mechanism 30 has X-axis slide rail 34 andX-axis slider 36. X-axis slide rail 34 is disposed on base 29 to extendin the X-axis direction. X-axis slider 36 is held by X-axis slide rail34 to be slidable in the X-axis direction. Further, X-axis slidemechanism 30 has electromagnetic motor (see FIG. 2) 38, and moves X-axisslider 36 to any position in the X-axis direction by drivingelectromagnetic motor 38. Furthermore, Y-axis slide mechanism 32 hasY-axis slide rail 50 and stage 52. Y-axis slide rail 50 is disposed onbase 29 to extend in the Y-axis direction and is movable in the X-axisdirection. A first end portion of Y-axis slide rail 50 is connected toX-axis slider 36. Stage 52 is held on Y-axis slide rail 50 to beslidable in the Y-axis direction. Further, Y-axis slide mechanism 32 haselectromagnetic motor (see FIG. 2) 56, and moves stage 52 to anyposition in the Y-axis direction by driving electromagnetic motor 56. Inthis manner, stage 52 is moved to any position on base 29 with drivingof X-axis slide mechanism 30 and Y-axis slide mechanism 32.

Stage 52 has base plate 60, holding devices 62, and lifting and loweringdevice 64. Base plate 60 is formed in a flat plate shape, and a board isplaced on an upper surface of base plate 60. Holding devices 62 areprovided on both sides of base plate 60 in the X-axis direction. Theboard placed on base plate 60 is fixedly held by sandwiching both edgeportions of the board in the X-axis direction with holding devices 62.In addition, lifting and lowering device 64 is disposed under base plate60, and lifts and lowers base plate 60.

First shaping unit 22 is a unit that shapes a wiring on the board placedon base plate 60 of stage 52, and has first printing section 72 andfiring section 74. First printing section 72 has inkjet head (see FIG.2) 76, and inkjet head 76 linearly discharges metal ink. The metal inkis ink obtained by dispersing nanometer-sized metal fine particles in asolvent. A surface of the metal fine particle is coated with adispersant and aggregation in the solvent is prevented. Inkjet head 76discharges the metal ink from multiple nozzles by, for example, a piezomethod using a piezoelectric element.

Firing section 74 has laser irradiation device (see FIG. 2) 78. Laserirradiation device 78 is a device that irradiates the discharged metalink with laser, and the metal ink irradiated with the laser is fired toform the wiring. Firing of the metal ink is a phenomenon in which energyis applied so as to vaporize the solvent and decompose a protective filmof the metal fine particle, that is, the dispersant, and the metal fineparticles are contacted or fused with each other, and thus conductivityis increased. Then, the metal ink is fired to form a metal wiring.

Further, second shaping unit 24 is a unit that shapes a resin layer onthe board placed on base plate 60 of stage 52, and has second printingsection 84 and curing section 86. Second printing section 84 has inkjethead (see FIG. 2) 88, and inkjet head 88 discharges an ultravioletcurable resin. The ultraviolet curable resin is a resin that is cured byirradiation with ultraviolet rays. Inkjet head 88 may be, for example, apiezo type inkjet head using a piezoelectric element, or may be athermal type inkjet head in which a resin is heated to generate airbubbles, which are discharged from multiple nozzles.

Curing section 86 has flattening device (see FIG. 2) 90 and irradiationdevice (see FIG. 2) 92. Flattening device 90 flattens an upper surfaceof the ultraviolet curable resin discharged by inkjet head 88, and forexample, scrapes up excess resin by a roller or a blade whilesmoothening the surface of the ultraviolet curable resin, to make thethickness of the ultraviolet curable resin uniform. Further, irradiationdevice 92 includes a mercury lamp or an LED as a light source, andirradiates the discharged ultraviolet curable resin with ultravioletrays. With this, the discharged ultraviolet curable resin is cured toform the resin layer.

Third shaping unit 26 is a unit that shapes a connection part between anelectrode of an electronic component and the wiring on the board placedon base plate 60 of stage 52, and has third printing section 100 andheating section 102. Third printing section 100 has dispense head (seeFIG. 2) 106, and dispense head 106 discharges conductive resin paste.The conductive resin paste is paste in which the micrometer-sized metalparticles are dispersed in a resin cured by heating. Incidentally, themetal particles are flake-shaped particles. Since a viscosity of theconductive resin paste is relatively high compared to that of the metalink, dispense head 106 discharges the conductive resin paste from onenozzle having a diameter larger than a diameter of the nozzle of inkjethead 76.

Heating section 102 has heater (see FIG. 2) 108. Heater 108 is a devicethat heats the discharged conductive resin paste, and a resin is curedin the heated conductive resin paste. At this time, in the conductiveresin paste, the cured resin is contracted, and the flake-shaped metalparticles dispersed in the resin come into contact with each other. As aresult, the conductive resin paste exhibits conductivity.

In addition, mounting unit 27 is a unit that mounts the electroniccomponent on the board placed on base plate 60 of stage 52, and hassupply section 110 and mounting section 112. Supply section 110 hasmultiple tape feeders (see FIG. 2) 114 that feed the taped electroniccomponents one by one, and supplies the electronic component to a supplyposition. Supply section 110 is not limited to tape feeder 114, and maybe a tray-type supply device that supplies the electronic component bypicking up the electronic component from a tray. Supply section 110 maybe configured to include both the tape-type and the tray-type, or othertype of supply device.

Mounting section 112 has mounting head (see FIG. 2) 116 and movingdevice (see FIG. 2) 118. Mounting head 116 has a suction nozzle (notshown) for picking up and holding the electronic component. The suctionnozzle picks up and holds the electronic component by picking up air asa negative pressure is supplied from a positive and negative pressuresupply device (not shown). As a slight positive pressure is suppliedfrom the positive and negative pressure supply device, the electroniccomponent is separated. In addition, moving device 118 moves mountinghead 116 between the supply position of the electronic component by tapefeeder 114 and the board placed on base plate 60. As a result, inmounting section 112, the electronic component supplied from tape feeder114 is held by the suction nozzle, and the electronic component held bythe suction nozzle is mounted on the board.

Further, as shown in FIG. 2, control device 28 includes controller 120and multiple drive circuits 122. Multiple drive circuits 122 areconnected to electromagnetic motors 38, 56, holding device 62, liftingand lowering device 64, inkjet head 76, laser irradiation device 78,inkjet head 88, flattening device 90, irradiation device 92, dispensehead 106, heater 108, tape feeder 114, mounting head 116, and movingdevice 118. Controller 120 includes CPU, ROM, RAM, or the like, mainlyincludes a computer, and is connected to multiple drive circuits 122.Accordingly, Controller 120 controls the operations of conveyance device20, first shaping unit 22, second shaping unit 24, third shaping unit26, and mounting unit 27.

With the configuration described above, in circuit formation device 10,a resin laminate is formed on board (see FIG. 3) 70, and the wiring isformed on an upper surface of the resin laminate. In the conventionalmethod, although the electrode of the electronic component is directlyconnected to the wiring, the adhesion between the resin laminate and thewiring is weak, therefore, when external stress is applied to theelectronic component, the wiring may be peeled off from the resinlaminate and be broken.

Specifically, board 70 is set on base plate 60 of stage 52, and stage 52is moved under second shaping unit 24. Then, in second shaping unit 24,resin laminate 130 is formed on board 70, as shown in FIG. 3. Resinlaminate 130 is formed by repeating discharge of the ultraviolet curableresin from inkjet head 88 and irradiation of the discharged ultravioletcurable resin with ultraviolet rays by irradiation device 92.

More specifically, in second printing section 84 of second shaping unit24, inkjet head 88 discharges the ultraviolet curable resin in a thinfilm shape onto an upper surface of board 70. Subsequently, when theultraviolet curable resin is discharged in a thin film shape, theultraviolet curable resin is flattened by flattening device 90 in curingsection 86, such that the ultraviolet curable resin has a uniform filmthickness. Then, irradiation device 92 irradiates the thin film-shapedultraviolet curable resin with ultraviolet rays. As a result, thinfilm-shaped resin layer 132 is formed on board 70.

Subsequently, inkjet head 88 discharges the ultraviolet curable resin ina thin film shape onto thin film-shaped resin layer 132. Then, the thinfilm-shaped ultraviolet curable resin is flattened by flattening device90, irradiation device 92 irradiates the ultraviolet curable resindischarged in a thin film shape with ultraviolet rays, and as a result,thin film-shaped resin layer 132 is laminated on thin film-shaped resinlayer 132. As described above, by repeating the discharge of theultraviolet curable resin onto thin film-shaped resin layer 132 and theirradiation of ultraviolet rays, multiple resin layers 132 are laminatedand resin laminate 130 is formed.

When resin laminate 130 is formed by the above-described procedure,stage 52 is moved under first shaping unit 22. Then, in first printingsection 72 of first shaping unit 22, inkjet head 76 linearly dischargesthe metal ink onto the upper surface of resin laminate 130 in accordancewith a circuit pattern. Subsequently, in firing section 74 of firstshaping unit 22, laser irradiation device 78 irradiates the metal inkdischarged in accordance with the circuit pattern with laser. As aresult, the metal ink is fired, and wiring 136 is formed on resinlaminate 130 as shown in FIG. 4.

Subsequently, when wiring 136 is formed on resin laminate 130, stage 52is moved under mounting unit 27. In mounting unit 27, electroniccomponent 138 is supplied by tape feeder 114 and electronic component138 is held by the suction nozzle of mounting head 116. Then, mountinghead 116 is moved by moving device 118, and electronic component 138held by the suction nozzle is mounted on the upper surface of resinlaminate 130 as shown in FIG. 5. At this time, electronic component 138is mounted on the upper surface of resin laminate 130, such thatelectrode 140 of electronic component 138 is in contact with wiring 136.In this manner, electronic component 138 is mounted on resin laminate130 in an electrifiable state to form the circuit.

Note that, since both wiring 136 and electrode 140 of electroniccomponent 138 are made of metal, the adhesion therebetween is high, butsince resin laminate 130 is made of resin, the adhesion to wiring 136 islow. Therefore, when external stress is applied to electronic component138, as shown in FIG. 6, electronic component 138 may be peeled off fromresin laminate 130 together with wiring 136, which is connected to theelectrode and wiring 136 may be broken.

In view of the above description, in circuit formation device 10,electrode 140 of electronic component 138 is not directly connected towiring 136 and is indirectly connected to wiring 136 via the conductiveresin paste. Specifically, when wiring 136 is formed on resin laminate130, the metal ink is discharged onto the upper surface of resinlaminate 130, such that an end portion of wiring 136 is not to overlapwith a disposition planned position of electrode 140 of electroniccomponent 138. That is, the metal ink is discharged onto the uppersurface of resin laminate 130, such that an end of the metal ink ispositioned outside an outer edge of the disposition planned position ofelectrode 140 of electronic component 138. In this manner, as shown inFIG. 7, wiring 136 is formed on the upper surface of resin laminate 130not to overlap with the disposition planned position of electrode 140 ofelectronic component 138. In FIG. 7, wiring 136 is formed on the uppersurface of resin laminate 130 not to overlap with not only thedisposition planned position of electrode 140, but also a dispositionplanned position of electronic component 138. Further, electroniccomponent 138 in FIG. 7 is marked with a dotted line to indicate thedisposition planned position of electrode 140, and electronic component138 does not exist at a time of work in FIG. 7.

As described above, when wiring 136 is formed not to overlap with thedisposition planned position of electrode 140, stage 52 is moved underthird shaping unit 26. Then, in third printing section 100 of thirdshaping unit 26, dispense head 106 discharges the conductive resin pasteonto the upper surface of resin laminate 130. At this time, conductiveresin paste 150, as shown in FIG. 8, is discharged onto the uppersurface of resin laminate 130 to be connected to the end portion ofwiring 136 and to extend to the disposition planned position ofelectrode 140. That is, conductive resin paste 150 is discharged, suchthat a first end portion is connected to the end portion of wiring 136,and a second end portion is positioned inside the outer edge of thedisposition planned position of electrode 140. Also, electroniccomponent 138 in FIG. 8 is marked with a dotted line to indicate thedisposition planned position of electrode 140, and electronic component138 does not exist at a time of work in FIG. 8.

Thus, when the conductive resin paste is discharged onto the uppersurface of resin laminate 130, stage 52 is moved under mounting unit 27.In mounting unit 27, electronic component 138 supplied by tape feeder114 is held by the suction nozzle of mounting head 116, and electroniccomponent 138 is mounted on the upper surface of resin laminate 130. Atthis time, as shown in FIG. 9, electronic component 138 is mounted onthe upper surface of resin laminate 130, such that electrode 140 ofelectronic component 138 is in contact with conductive resin paste 150.

Subsequently, when electronic component 138 is mounted, stage 52 ismoved under third shaping unit 26. In third shaping unit 26, heater 108heats conductive resin paste 150 in heating section 102. As a result,conductive resin paste 150 exhibits the conductivity, electrode 140 ofelectronic component 138 is electrically connected to wiring 136 viaconductive resin paste 150.

Thus, when electrode 140 of electronic component 138 is electricallyconnected to wiring 136 via conductive resin paste 150, electrode 140adheres to conductive resin paste 150, and conductive resin paste 150adheres to resin laminate 130. As described above, conductive resinpaste 150 in which the flake-shaped metal particles dispersed in theresin are in contact with each other in the cured resin is made of aresin material and a metal material. Therefore, the adhesion betweenelectrode 140 and conductive resin paste 150 is high, and the adhesionbetween conductive resin paste 150 and resin laminate 130 is also high.As a result, even when external stress is applied to electroniccomponent 138, it is possible to prevent electronic component 138 frombeing peeled off from resin laminate 130, and prevent wiring 136 frombeing broken.

Further, since conductive resin paste 150 is made of the resin materialand the metal material, the conductivity thereof is low compared towiring 136, but a disposition location of conductive resin paste 150 isa small area under electrode 140. Therefore, the decrease inconductivity due to conductive resin paste 150 is very small.

In addition, as described above, the metal ink is discharged by inkjethead 76 because the viscosity of the metal ink is low and the conductiveresin paste is discharged by dispense head 106 because the viscosity ofthe conductive resin paste is high. Therefore, it is possible todischarge the metal ink, which is the base of wiring 136 constitutingmost of the circuit, with high accuracy, to form a dense circuit.

Furthermore, by connecting electrode 140 and wiring 136 via conductiveresin paste 150 made of the resin material and the metal material, typesof the ultraviolet curable resin and the metal ink can be easilyselected. That is, in a case where electrode 140 and wiring 136 aredirectly connected to each other as in the conventional art, the typesof the ultraviolet curable resin and the metal ink are selected inconsideration of each of raw materials in order to increase the adhesionbetween wiring 136 and resin laminate 130 as much as possible. On theother hand, in a case where conductive resin paste 150 is used, it isnot necessary to consider the adhesion between wiring 136 and resinlaminate 130, and therefore, the types of the ultraviolet curable resinand the metal ink can be easily selected.

Controller 120 of control device 28 includes base formation section 160,wiring formation section 162, paste application section 164, andcomponent placement section 166 as shown in FIG. 2. Base formationsection 160 is a functional section for forming resin laminate 130.Wiring formation section 162 is a functional section for forming wiring136. Paste application section 164 is a functional section fordischarging conductive resin paste 150. Component placement section 166is a functional section for placing electronic component 138.

Second Embodiment

In the first embodiment, conductive resin paste 150 is formed to beconnected to the end portion of wiring 136, whereas in the secondembodiment, conductive resin paste 150 is formed on wiring 136. Morespecifically, when wiring 136 is formed on resin laminate 130, the metalink is discharged onto the upper surface of resin laminate 130 in thesame manner as in the conventional method. That is, the metal ink isdischarged onto the upper surface of resin laminate 130, such that theend of the metal ink is positioned inside the outer edge of thedisposition planned position of electrode 140 of electronic component138. As a result, as shown in FIG. 4, wiring 136 having the same shapeas the conventional method is formed on the upper surface of resinlaminate 130.

Subsequently, when wiring 136 is formed, stage 52 is moved under thirdshaping unit 26. Then, in third printing section 100 of third shapingunit 26, dispense head 106 discharges conductive resin paste 150 ontowiring 136. At this time, conductive resin paste 150, as shown in FIG.10, is discharged onto the disposition planned position of electrode 140in an upper surface of wiring 136. Conductive resin paste 150 isdischarged to cover the end portion of wiring 136. As a result, as shownin FIG. 12, conductive resin paste 150 covers the entire end portion ofwiring 136, and an edge portion thereof adheres to the upper surface ofresin laminate 130.

Then, when conductive resin paste 150 is discharged to cover the endportion of wiring 136 at the disposition planned position of electrode140, stage 52 is moved under mounting unit 27. In mounting unit 27,electronic component 138 is held by the suction nozzle of mounting head116, and electronic component 138 is mounted on the upper surface ofresin laminate 130. At this time, as shown in FIG. 11, electroniccomponent 138 is mounted on the upper surface of resin laminate 130,such that electrode 140 of electronic component 138 is in contact withconductive resin paste 150.

Subsequently, when electronic component 138 is mounted, stage 52 ismoved under third shaping unit 26, and heater 108 heats conductive resinpaste 150 in heating section 102. As a result, conductive resin paste150 exhibits the conductivity, electrode 140 of electronic component 138is electrically connected to wiring 136 via conductive resin paste 150.

Like this, when conductive resin paste 150 is discharged to cover theend portion of wiring 136 at the disposition planned position ofelectrode 140, electrode 140 of electronic component 138 is electricallyconnected to wiring 136 via conductive resin paste 150. As a result, acircuit of the second embodiment exhibits the same effect as the circuitof the first embodiment. In the circuit of the second embodiment, asshown in FIG. 12, conductive resin paste 150 between electrode 140 andwiring 136 is electrified by the film thickness of conductive resinpaste 150. Therefore, the decrease in conductivity due to conductiveresin paste 150 can be minimized.

On the other hand, in a method of the second embodiment, conductiveresin paste 150 covers the end portion of wiring 136, and an occupiedarea of conductive resin paste 150 is increased. Therefore, when adistance between the electrodes in electronic component 138 is small,conductive resin paste 150 connected to one electrode and conductiveresin paste 150 connected to the other electrode is brought into contactwith each other, and a short circuit may occur. In consideration of theabove, when a circuit including an electronic component in which thedistance between the electrodes is small is formed, it is preferable toadopt the circuit formation method of the first embodiment.

In the above embodiment, circuit formation device 10 is an example of acircuit formation device. Control device 28 is an example of a controldevice. Inkjet head 76 is an example of a first application device.Laser irradiation device 78 is an example of a firing device. Dispensehead 106 is an example of a second application device. Mounting head 116is an example of a holding device. The metal ink is an example of ametal-containing liquid. Resin laminate 130 is an example of a base.Resin layer 132 is an example of a resin layer. Wiring 136 is an exampleof a wiring. Electronic component 138 is an example of a component.Electrode 140 is an example of an electrode. Conductive resin paste 150is an example of a resin paste. Wiring formation section 162 is anexample of a wiring formation section. Paste application section 164 isan example of a paste application section. Component placement section166 is an example of a component placement section. A step performed bybase formation section 160 is an example of a base formation step. Astep performed by wiring formation section 162 is an example of a wiringformation step. A step performed by paste application section 164 is anexample of a paste application step. A step performed by componentplacement section 166 is an example of a component placement step.

The present disclosure is not limited to the embodiments describedabove, and can be implemented in various embodiments with variousmodifications and improvements based on the knowledge of those skilledin the art. For example, in the above embodiment, a resin cured byheating is adopted as conductive resin paste 150, but a resin cured byirradiation with ultraviolet rays or the like may be adopted.

In the above embodiment, conductive resin paste 150 is discharged toresin laminate 130 by dispense head 106, but conductive resin paste 150may be transferred to resin laminate 130 by a stamp. In addition,conductive resin paste 150 may be printed on resin laminate 130 byscreen printing.

REFERENCE SIGNS LIST

10 Circuit formation device, 28 control device, 76 inkjet head (firstapplication device), 78 laser irradiation device (firing device), 106dispense head (second application device), 116 mounting head (holdingdevice), 130 resin laminate (base), 132 resin layer, 136 wiring, 138electronic component (component), 140 electrode, 150 conductive resinpaste (resin paste), 160 base formation section (base formation step),162 wiring formation section (wiring formation step), 164 pasteapplication section (paste application step), 166 component placementsection (component placement step)

1. A circuit formation method comprising: a wiring formation step offorming a wiring by applying a metal-containing liquid containingnanometer-sized metal fine particles onto a base and firing themetal-containing liquid; a paste application step of applying a resinpaste containing micrometer-sized metal particles to be connected to thewiring formed in the wiring formation step; and a component placementstep of placing a component having an electrode on the base, such thatthe electrode is in contact with the resin paste applied in the pasteapplication step.
 2. The circuit formation method according to claim 1,wherein the paste application step is a step of applying the resin pasteon the wiring formed in the wiring formation step.
 3. The circuitformation method according to claim 1, wherein the paste applicationstep is a step of applying the resin paste to be connected to an endportion of the wiring formed in the wiring formation step.
 4. Thecircuit formation method according to claim 1, further comprising: abase formation step of forming the base by curing a curable resinapplied in a thin film shape to form a resin layer and laminating theresin layer.
 5. A circuit formation device comprising: a firstapplication device configured to apply a metal-containing liquidcontaining nanometer-sized metal fine particles; a second applicationdevice configured to apply a resin paste containing micrometer-sizedmetal particles; a firing device configured to fire the metal-containingliquid; a holding device configured to hold a component having anelectrode; and a control device, wherein the control device includes awiring formation section configured to form a wiring by applying themetal-containing liquid onto a base by the first application device andfiring the metal-containing liquid by the firing device, a pasteapplication section configured to apply the resin paste by the secondapplication device to be connected to the wiring formed by the wiringformation section, and a component placement section configured to placethe component on the base by the holding device, such that the electrodeis in contact with the resin paste applied by the paste applicationsection.